13439
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 13680
- Proper Divisor Sum (Aliquot Sum)
- 241
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 13200
- Möbius Function
- 1
- Radical
- 13439
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 244
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- Squarefree Number
- yes
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Number of trees on n nodes with 3 forbidden limbs of size 4, 5 and 6.at n=14A014280
- Numbers k > 1 such that k mod ord2(k) is even, where ord2(k) is the order of 2 mod k.at n=21A036260
- Expansion of (1-x)^(-1)/(1-2*x+2*x^2-2*x^3).at n=20A077858
- Expansion of 1/(1-2*x+x^2+x^3).at n=25A077941
- Expansion of 1/(1+x^2+x^3).at n=53A077962
- Expansion of (1-x)/(1 + x^2 - x^3).at n=51A078031
- Number of parts in all compositions of n into distinct parts.at n=20A097910
- Odd numbers n for which 19 is the smallest i (>= 1) with Jacobi symbol J(i,n) getting either a value 0 or -1.at n=6A112078
- Least k such that the Collatz (3x+1) iteration starting with k has "dropping time" A122437(n).at n=42A122442
- a(n) = n!/3 - 1.at n=5A139173
- A144325(n) + A144313(n) + A144315(n).at n=29A144715
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, -1, 1), (0, 0, 1), (0, 1, -1), (1, 0, -1)}.at n=10A148503
- Numbers of the form ((6k+5)^2+9)/2 or 2(3k+4)^2-9.at n=53A214493
- n - (sum of prime factors of n^2+1) is a positive square.at n=38A216896
- G.f. satisfies A(x) = 1 + x*A(x)^3 / (1 - x*A(x)^2)^2.at n=6A367238
- Triangle read by rows: T(n,k) is the numerator of the probability of winning a 1-player game M(n,k) as defined below while playing optimally.at n=46A370398